"Philly"and soft pretzel - to me, anyway - isn't really a "best of" kind of thing. THere are a lot of bad ones, but there are also tons of places that give you a perfectly good soft pretzel. Just make sure it's from today, and don't get a fancy one or one from Auntie Anne's. Some people will say the ones in Reading Terminal are best and, while I like them - and you should got o Reading Terminal - they're a different kind of beast. I like them once in a while, but overal prefer the ones that most any hot dog stand will have.

Tony Lukes is very good if you have a car. But if you're getting a car and going that far (assuming you're not staying in South Philly/Stadiums/Airport), John's Roast Pork is excellent as well, and a good bit better in my mind. They are not open Saturday, and the grill shuts off at 2 or 2:30, however. If you're taking public transit, it may be bit of a pain either way (unless you're staying in Old City or on Columbus Blvd) but John's is a good bit closer.

There's lots of good breakfast options in that range. Depends on where you are and how far you're willing to go. I'll throw out Kanella a unique and delicious brunch experience, but they don't open until 10:00 on Friday & Saturday and 11:30 on Thursday. You'll spend closer to $15-20 or so after drinks and tax/tip, and you may want to get a reservation for Saturday.

For soft pretzel, I agree with Bob, just get it off any street vendor. It's a bit of a gamble on how fresh it is, but they also only cost $0.50 each. Thursday and Friday morning/lunchtime should be pretty safe in the busy parts of Center City and West Philly. Miller's in Reading Terminal Market has awesome soft pretzels, and are worth it, but are not the traditional Philly soft pretzel street food.

And yes definitely walk around Reading Terminal Market, in the morning through early afternoon. They close around 6:00 and many vendors call it quits before that. You should consider getting a roast pork sandwich from DiNics in the market instead of going to Tony Luke's, TL is good but the DiNics sandwich is as good or better than anything they have, and it's more accessible.

The Italian Market is interesting and bustling on Saturdays. You can get great "Philly-style" sandwiches down there as well (no cheesesteak), at Paesano's (note new location: 1017 S 9th Street), and again as good or better than anything at TL's.